1. Field of the Invention
The present invention relates to benzotriazolyl-alkylene bisphenol compounds which function as both light stabilizing agents and antioxidants, to a process for their preparation, and to organic materials stabilized by those compounds.
2. Description of the Related Art
2-hydroxyphenylbenzotriazole compounds are known as light stabilizers for synthetic resins and the like, but because these compounds are of lower molecular weight than the compounds of the invention to be described hereunder, and thus undergo volatilization during working of resins and with the passage of time, they have not been able to stabilize organic materials for extended periods. Also, antioxidants consisting mainly of alkyl-substituted phenols, represented by 2,6-di-tert.-butyl-p-cresol, as well, have been unable to provide long-term stabilization of organic materials for the same reason.
Czechoslovakian Patent No. 157,761 discloses preparation of benzotriazolyl-alkylene bisphenol compounds by a process involving synthesis of the corresponding substituted 2,2'-methylenebisphenol, coupling the bisphenol compound with o-nitrobenzene diazonium salt, and then reducing and cyclizing it by common methods. However, this patent does not disclose the yields, nor have the present inventors been able to confirm production of the desired compounds by reproducing the examples or carrying out the synthesis experiments. The process is therefore deemed to be completely impractical.